We have a light switch box containing three single pole switches (no ground terminal) in the foyer near the front door. I wish to replace the sunshine switch controlling the porch lights with the Honeywell Programmable Timer Switch RPLS740B. Given the following conditions, I couldn’t determine any wiring combination such that every one related electrical components worked.
Here is an image of the particular timer followed by its simple wiring diagram:
The light switch box consists of a switch that controls nothing, a switch that controls the chandelier within the foyer, and a switch that controls the front porch lights (in that order). Note that the primary switch affects no known electrical appliance for sure. Whether this is due to improper or faulty wiring I’m unsure. Also, this is all the original wiring (as built).
The light switch box also consists of 1 “three-wire” cable (red, black, white, copper) and 5 “two-wire” (black, white, copper) cables. Note that these are also termed “four-wire” and “three-wire” respectively.
The unique wiring setup seems rather simple in that each one ground wires are tied together, all black wires are tied together, and all white wires are tied together. Each of the switches is connected to the one black wire belonging to the “two-wire” cable at the bottom of the box, which I assume to be the “line”. However, since all of the black wires are tied together, this appears to be inconsequential.
Simply replacing the porch light switch with the timer as expected doesn’t work at all. Freeing particular white “neutral” wires does cause the timer to function but would also cause various fans/lights in the adjacent study to stop functioning. Is it common for a light switch box to have so many incoming cables? Why does the primary switch even need a red wire if its a single pole switch?
I mistakenly assumed that the line was located at the bottom of the switch box when the truth is it was the first cable at the highest. With this knowledge I was able to determine the unknown loads as seen below (for future reference).